An X-ray diagnostic apparatus irradiates a subject with an X-ray and detects the X-ray that has passed through the subject to display as an X-ray image, through which conditions of organs or blood vessels inside a body or the like can be perceived. However, in a case where the subject is irradiated with an excessive dose of X-rays, there is a risk that an inflammation or the like is caused in a skin. Therefore, it is required to control an exposure dose of the subject.
In order to control the exposure dose, some conventional X-ray diagnostic apparatuses are provided with a means with which a dose distribution is expressed by different colors to be displayed on a surface of a human body model representing the subject such that an operator can visually determine the dose distribution. When the dose distribution is displayed, the human body model is fixed to one direction such as a ventral surface, a back surface, or a side surface of the subject.
In the conventional X-ray diagnostic apparatus, however, the human body model displayed in a direction in which the dose distribution of a desired site is visible is sometimes different from an actual condition of the subject observed by the operator. In this case, a position of an X-ray generator or an arm relative to the subject is difficult to recognize. Therefore, it is not easy to determine an irradiation range of the X-ray.